Capability of future linear colliders to discover heavy neutral CP-even and CP-odd Higgs bosons within type-I 2HDM

Abstract

In this study, assuming the type-I 2HDM at standard model-like scenario, observability of heavy neutral CP-even and CP-odd Higgs bosons H and A at a linear collider operating at TeV is investigated through the signal process chain where the Z boson experiences a leptonic ( or ) decay and the H Higgs boson is assumed to decay into a di-photon. This signal process is motivated especially by the clean signature which leptonic and photonic events can provide at colliders, and also by the enhancement due to the charged Higgs-mediated contribution to H di-photon decay at large values. The simulation is based on four benchmark points according to which the Higgs mass mH (mA) varies within the range 150–300 (200–400) GeV. Energy smearing of jets and photons is performed, and momentum smearing is also applied to leptons. Results indicate that, for all of the assumed benchmark points, the Higgs bosons H and A are observable with measurable masses, and with signals exceeding 5σ at integrated luminosities 99 and , respectively. Such luminosities are easily accessible to future linear colliders.